Note: Descriptions are shown in the official language in which they were submitted.
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IP
1
SPECIFICATION
TITLE OF THE INVENTION
PLASTIC BAG MAKING APPARATUS
TECHNICAL FIELD OF THE INVENTION
[0001] The invention relates to an apparatus for
successively making plastic bags.
BACKGROUND OF THE INVENTION
[0002] In an apparatus for successively making plastic
bags from plastic films, some wastes are often formed while
the plastic bag is made, as described in Patent Document 1.
In the case of the apparatus of Patent Document 1, the wastes
are suctioned in and discharged from a suction path. The
apparatus comprises an optical sensor for detecting the
wastes when being suctioned. When the waste is not
discharged from the suction path, an action such as an alarm
is performed by a controller. Therefore, there is no case
that an undischarged waste is attached to the plastic film
and fed intermittently. As a result, there is no problem of
the waste being introduced into the plastic bag.
[0003] On the other hand, in an apparatus described in
Patent Document 2, the plastic films are fed intermittently
by feed rollers and slit along its longitudinal slit line.
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Then, the plastic films are cross cut by a cutter when
stopped temporarily so as to make the plastic bags. In the
apparatus, the plastic films are punched by punch blades when
stopped temporarily so as to form corner cut areas in the
plastic bags. Then, the plastic films are cross cut by the
cutter two times whenever making each of the plastic bags.
Therefore, the plastic films are cross cut at both sides
across its widthwise cut line. As a result, any projected
uneven edge is not formed at the corner cut area of the
plastic bag.
[0004] By the way, in the apparatus of Patent Document 2,
a plurality of wastes is formed in at least two areas
adjacent to each other widthwise of the plastic bag because
the plastic films are cross cut at the both sides across the
widthwise cut line of the plastic bag after being slit and
punched. In this case, as the apparatus of Patent Document 1,
the wastes can be detected by the optical sensor after being
suctioned in and discharged from a suction path. However,
the apparatus cannot determine or examine whether all of
wastes of each of areas are discharged even if the wastes are
detected. Therefore, the undischarged waste may be attached
to the plastic film and introduced into the plastic bag.
[0005] It is therefore an object of the invention to
provide an apparatus for successively making the plastic bags,
wherein the wastes are formed in at least two areas adjacent
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to each other widthwise of the plastic film, and the
apparatus can determine whether all of wastes of each of the
areas are discharged.
[0006]
Patent Document 1: JP 2003-326616A
Patent Document 2: JP 2,805,515B
SUMMARY
[0007] According to the invention, an airflow is generated
in a suction path so as to suction the waste of each of the
areas. Further, at least one partition plate is disposed in
the suction path in such a way that the suction path is
divided widthwise of the plastic film into at least two. The
waste is guided to each of the divided paths and is
discharged. The waste is detected by an optical sensor when
being discharged to each of the divided paths. A controller
is connected with the optical sensor. An action such as an
alarm is performed by the controller when the waste is not
discharged to each of the divided paths.
20 [0008] According to another preferable embodiment, the
waste is detected at more than two detect positions which are
determined and spaced from each other in a direction of the
airflow and in each of the divided paths.
[0009] Further, the controller determines that the waste
is discharged when being detected at any one of the detect
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positions. Its detect level may be changed appropriately
depending on the specification required for the plastic bag.
[0010] The optical sensor may be configured to detect that
the wastes are generated in at least two areas, and be composed
of, for example, a digital camera that converts an imaging
information imaged on an image sensor thereof such as CCD into
an electric signal. Concretely, the digital camera is opposed to
the divided paths, a detect area of the digital camera includes
each of the detect positions. An electronic shutter of the
digital camera is actuated so as to detect the wastes when the
wastes pass through each of the detect positions.
[0011] A pair of a projector and a receiver may be used as
optical sensor.
[0012] A material with an antistatic property may be used
for each wall of each of the divided paths preferably.
[0013] A high airtight material may be used for each wall
of each of the divided paths preferably.
[0014] Each of the divided paths may have a smooth flow
channel geometry preferably.
[0015] The partition plate may be configured to be moved
widthwise of the plastic film preferably.
[0015a] Some embodiments disclosed herein provide an
apparatus for successively making plastic bags from a plastic
film by which wastes being formed in at least two areas
adjacent to each other widthwise of the plastic film, the
apparatus comprising: a suction path configured to generate an
Date Recue/Date Received 2021-03-16
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airflow, the wastes in the areas can be suctioned by the
airflow; at least one partition plate configured to divide the
suction path widthwise of the plastic film into at least two
divided paths, the partition plate being disposed in the
suction paths, the wastes being guided to each of the divided
paths and being discharged; an optical sensor configured to
detect the wastes discharged to each of the divided paths; and
a controller configured to perform an action such as an alarm
when the wastes are not discharged to each of the divided
paths, the controller being connected with the optical sensor,
wherein the partition plate is configured to be moved in a
widthwise direction relative to the plastic film.
BRIEF DESCRIPTION OF THE DRAWING
[0016]
Date Recue/Date Received 2021-03-16
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Fig. 1 is a plan view of a preferred embodiment of
the invention.
Fig. 2 is a side view of the apparatus of Fig. 1.
Fig. 3 is an explanatory view showing wastes of
5 plastic films of Fig. 1.
Fig. 4 is a front view of a chute of Fig. 2.
Fig. 5 is a front view of the chute of Fig. 4 on
which projectors and receivers are disposed as optical
sensors.
Fig. 6A is a side view showing a relation between
parts of Fig. 2 precisely.
Figs. 6B to 6D are sectional views in a direction A
of Fig. 6A.
DETAILED EXPLANATION OF THE PREFERRED EMBODIMENTS
[0017] Embodiments of the invention are as follows.
[0018] Turning now to the drawings, Fig. 1 illustrates an
apparatus for successively making plastic bags.
In the apparatus, a plastic film 1 is nipped between a pair
of feed rollers 2 after being heat sealed so as to be fed
intermittently by the feed rollers 2. Its feed direction X
is extended longitudinally of the plastic film 1. Then, the
plastic film 1 is slit by a slit blade 3 at an upstream side
of the feed rollers 2. The slit blade 3 is composed of a
razor blade by which the plastic film 1 is slit along a
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longitudinal slit line 4. The longitudinal slit line 4 is
the same as a center line of a longitudinal seal area of the
plastic film 1.
[0019] Then, the plastic film 1 is cross cut by a cutter
whenever the plastic film 1 is fed intermittently so as to
make plastic bags. As shown in Fig. 2, the cutter is
composed of a guillotine blade which includes an upper blade
5 and a lower blade 6. The upper blade 5 is lowered by a
drive mechanism, so that the plastic film 1 is nipped between
the upper and lower blades 5 and 6 by which the plastic film
1 is cross cut. Then, the upper blade 5 is elevated by the
drive mechanism so as to be returned. Specifically, the
upper blade 5 is moved in a vertical direction Z. The
plastic film 1 is cross cut along its widthwise cut line 7.
[0020] At the upstream side of the feed rollers 2 and the
slit blade 3, the plastic film 1 is punched by a punch blade
8 whenever the plastic film 1 is fed intermittently so as to
form corner notches 9. The corner notch 9 is formed at an
intersection of the longitudinal slit line 4 and the
widthwise cut line 7. At the same time, the plastic film 1
is punched by punch blades 10 so as to form corner notches 11
in the plastic film 1. The corner notches 11 are formed at
the widthwise cut line 7 and both side edges of the plastic
film 1. Therefore, the plastic bag is corner cut by the
corner notches 9 and 11 when the plastic film 1 is cross cut
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so as to make the plastic bag.
[0021] The plastic film 1 is punched by the punch blade 12
so as to form open notches 13 at the same time when the
corner notches 9 and 11 are formed. The open notches 13 are
formed at the widthwise cut line 7 and between each of the
corner notches 9 and 11. Therefore, the plastic bag can be
ripped from the open notch 13 so as to be opened.
[0022] Then, the plastic films are cross cut by the cutter
two times whenever making each of the plastic bags.
Therefore, the plastic films are cross cut at the both sides
across the widthwise cut line 7 (Fig. 3). For example,
similarly to the apparatus of Patent Document 2, the plastic
film 1 is cross cut at the front side of the widthwise cut
line 7, and then the upper and lower blades 5 and 6 are moved
to the rear side of the widthwise cut line 7 so as to cross
cut the plastic film 1 at the rear side of the widthwise cut
line 7. And then, the upper and lower blades 5 and 6 are
moved and returned to the front side of the widthwise cut
line 7. In the same way, the widthwise cut line 7 is
disposed at a position where top areas of the corner notches
9 and 11 and the open notches 13 can be connected with each
other. The plastic film 1 is cross cut at the front and rear
sides across the widthwise cut line 7. As a result, a
projected uneven edge cannot be formed at the corner cut
areas of the plastic bag.
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[0023] In the apparatus, a plurality of wastes 14 is
formed at more than two areas adjacent to each other
widthwise Y of the plastic film 1 because the plastic film 1
is cross cut at the both sides across the widthwise cut line
7 of the plastic film 1 after being slit and punched. In
this embodiment, the plastic film 1 is punched by the punch
blades 8, 10 and 12 so as to form the corner notches 9 and 11
and the open notches 13. Therefore, the wastes 14 are formed
at four areas 15A, 15B, 150 and 15D adjacent to each other
widthwise Y of the plastic film 1 when the plastic film 1 is
cross cut.
[0024] The open notches 13 are usually disposed near the
upper side of the plastic bag (a pouch). However, in the
case of Figs. 3 to 5, the open notches 13 are disposed near
the center of the plastic bag for convenience sake because
the positions thereof are no relation with the spirit of the
invention.
[0025] In the embodiment, as shown in Fig. 2, an airflow
17 is generated in a suction path 16 so as to suction the
wastes 14 of the areas 15A, 15B, 150 and 15D. In the
embodiment, the suction path 16 is formed in a hollow chute
18. The upper end of the chute 18 is opposed to the upper
blade 5, while the lower end thereof is connected with a
suction duct. The lower blade 6 is fixed to a base 19 which
is fixed to the chute 18. Therefore, the chute 18 are moved
-
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...
integrally with the lower blade 6 when the upper and lower
blades 5 and 6 are moved to the front and rear sides of the
widthwise cut line 7. The suction path 16 is evacuated by
the suction duct so as to generate the airflow 17 in the
suction path 16. Thus, the waste 14 is suctioned in the
suction path 16 so as to be discharged to the suction duct
when the plastic film 1 is cross cut at the both sides across
the widthwise cut line 7.
[0026] As shown in Fig. 4, the chute is fan-shaped. At
least one partition plate 20 is disposed on the suction path
16 so as to divide the suction path 16 into at least two
areas widthwise Y of the plastic film 1. The wastes 14 are
guided and discharged to the divided paths. In the
embodiment, a total of three of the partition plates 20 are
disposed on the suction path 16 so as to divide the suction
path 16 into four areas. The wastes 14 are guided and
discharged to the divided paths 21A, 21B, 21C and 21D
respectively. The partition plates 20 are extended along the
suction path 16 and spaced from each other widthwise Y of the
plastic film 1. The divided paths 21A, 21B, 21C and 21D have
spaces corresponding to the areas 15A, 15B, 15C and 15D
respectively (Fig. 3). Therefore, the wastes 14 of the areas
15A, 153, 15C and 15D are reliably suctioned and discharged,
respectively.
[0027] The wastes 14 are detected by an optical sensor
.,
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when being discharged to the divided paths 21A, 21B, 21C and
21D respectively. In the embodiment, the wastes 14 are
detected at more than two detect positons 22 and 22 which are
determined and spaced from each other in a direction of the
5 airflow 17 and in each of the divided paths 21A, 21B, 21C and
21D. For example, the wastes 14 are detected at two of the
detect positions 22 and 22 which are determined and spaced
from each other in a direction of the airflow 17.
[0028] As shown in Fig. 2, the optical sensor is composed
10 of a digital camera 23 which can convert an imaging
information imaged on an image sensor thereof such as CCD
into an electric signal. The digital camera 23 is opposed
toward the divided paths 21A, 21B, 21C and 21D. Its detect
area 24 includes each of the detect positions 22. As shown
in Fig. 4, the electronic shutter of the digital camera is
actuated to detect the waste 14 when the waste 14 passes
through the detect position 22. The number of the cameras 23
is determined depending on the specification of the camera 23.
For example, in the case of Fig. 4, two cameras can be used
as one is for the divided paths 21A and 21B and the other is
for the divided paths 21C and 21D. Each of the cameras 23 is
opposed toward the chute 18 and the divided paths 21A, 21B,
210 and 21D. The electric shutter of the digital camera 23
is actuated when the waste 14 passes through the detect
position 22. The chute 18 is made of a clear glass or a
..
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clear plastic material in the detect area 24. The camera 23
can detect the waste 14 through the clear glass or the clear
plastic material, which is disposed even on the outside of
the chute 18.
[0029] The apparatus includes a controller 26 which is
connected with the optical sensor. When the waste 14 is not
discharged to the divided paths 21A, 21B, 21C and 21D, an
action such as an alarm is performed by the controller 26.
In the embodiment, the controller 26 determines that the
waste 14 is discharged when the waste 14 is detected at one
of two of the detect positions 22 and 22. For example, the
controller 26 determines that the waste 14 is discharged when
the waste 14 is detected at both of the two detect positions
22 and 22. In the same way, the controller 26 determines
that the waste 14 is discharged when the waste 14 is detected
at one of the two detect positions 22 and 22. Thus, the
controller 26 determines that the waste 14 is not discharged
when the waste 14 is not detected at both of the two detect
positions 22 and 22. Therefore, the action such as the alarm
is performed by the controller 26.
[0030] In the apparatus, the waste 14 is detected by the
camera 23 when being discharged to the divided paths 21A, 21B,
21C and 21D. Therefore, the apparatus can determine whether
or not all of the wastes 14 of the areas 15A, 15B, 15C and
15D are discharged. The action such as the alarm is
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performed when any one of the wastes 14 is not discharged to
the divided paths 21A, 21B, 21C and 21D. Therefore, there is
no chance that the undischarged waste 14 is attached to the
plastic film 1 and introduced into the plastic bag.
[0031] The waste 14 may not be detected for some reason
even if the waste 14 is discharged to the divided paths 21A,
21B, 21C and 21D. However, in the apparatus, the waste 14
can be detected at more than two of the detect positions 22
and 22. Therefore, the action such as the alarm is not
performed by mistake because the waste 14 can be detected by
the other detect position 22 even if the waste 14 cannot be
detected by the particular detect position 22. Thus, the
action such as the alarm is performed when the waste 14 is
not detected at two of the detect positions 22 and 22
disposed at the upstream and downstream of the divided paths
21A. On the other hand, the action is not performed because
the apparatus determines that the waste 14 is flowed through
the divided paths 21A when the waste 14 is detected at either
one of two of the detect positions 22 and 22.
[0032] As shown in Fig. 2, the camera 23 may be opposed to
each of the divided paths 21A, 21B, 210 and 21D in such a way
that the detect area 24 thereof can include each of the
detect positions 22. In this way, the waste 14 can be
efficiently detected by the common camera 23 in a low cost.
[0033] Such detection can be operated by a known signal
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processing technology. For example, the waste 14 can be
detected by comparison between each of image data in a
plurality of image areas before and after a predetermined
time, the image data in the image areas are arbitrarily
selected and memorized in a memory.
[0034] As a concrete structure, the camera 23 can for
example image the whole of the fan-shaped part of the chute
18 of Fig. 4. At fast, the fan-shaped part of the chute 18
is imaged by the camera 23 before the waste 14 is suctioned
in the chute 18, that is to say, before the plastic film 1 is
cross cut by the upper and lower blades 5 and 6. The image
data are memorized as data before cut. Then, the electronic
shutter of the camera 23 is opened during a predetermined
time from when the plastic film 1 is cross cut. The image
data imaged by the camera during the time are memorized as
data after cut. Then, the image data in the areas Al to A4
and Bl to B4 of Fig. 4 are compared with each other by using
the data before and after cut. When the data before and
after cut of at least one of four pairs composed of the areas
Al and Bl, the areas A2 and B2, the areas A3 and B3 and the
areas A4 and B4 are the same respectively, the apparatus
determines that the waste 14 is not passed through both the
upstream side (the area A) and the downstream side (the area
B). As a result, the alarm is raised and the apparatus is
stopped before the cross cut is operated. For example, when
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the data before and after cut in the area Al are the same
respectively but the data in the area Bl are different
respectively for some reasons, the waste 14 passed through
the area Al may not be detected for some error. However, the
apparatus determines that the waste is passed through the
path between the areas Al and Bl and the alarm is not raised.
This is defined as an algorithmic pattern 1.
[0035] The waste 14 can be kept from introducing into the
plastic film 1 by operating the algorithmic pattern 1.
[0036] In the case that the introduction of a foreign
matter is completely unacceptable, for example the pouch is
made and used for medical purposes, the alarm is raised when
the data before and after cut of any one of eight of the
areas Al to A4 and Bl to B4 are the same respectively by
using stricter algorithm.
[0037] For example, in the case that the waste 14
generated at the time of the first cut is passed through the
area Al but attached to the inside wall of the chute 18 in
front of the area Bl, if the attached waste 14 is passed
through the area Bl at the time of the second cut and
detected, the apparatus determines that the waste 14 is
passed through the path from the area Al to the area Bl at
the time of both the first and second cuts by using the
algorithmic pattern 1. However, there is possible that the
waste 14 remains attached and is not discharged at the time
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of the second cut. In this case, the alarm has to be raised
by using another algorithmic pattern because the waste is not
detected at the time of the first cut. This pattern is
defined as an algorithmic pattern 2.
5 [0038] The algorithmic pattern 2 is operated, so that the
introduction of the waste 14 can be prevented reliably.
[0039] The data before cut can be memorized before the
waste 14 is generated. The word "predetermined time" may
mean an enough time from when the cross cut is operated till
10 when the waste 14 is suctioned in the chute 18 and arrived at
the areas Bl to B4.
[0040] The apparatus can display the image through the
camera 23 on an operation panel in such a way that the
operator can select the image areas via the displayed image.
15 For example, the operation panel is composed of a touch type
operation panel, and the area Al can be defined by touching
the four corners of the partitioned area Al by using a touch
pen. Another area can be defined in the same way. Thus, the
defined area can be changed even if the position of the
partition plate 20 is changed in the chute 18. The camera 23
may be composed of any type of camera that can electrically
convert the image into an image signal via an image sensor
such as CCD, CMOD and FOVION sensor.
[0041] The airflow 17 is generated so as to suction the
waste 14, however the waste 14 is attached to the inside of
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the chute 18 and is not discharged if the length thereof is
so long. In this case, the waste 14 may be waved, so that
the apparatus may determine that the waste 14 is passed
through the detect positions 22 and 22 by mistake even though
the waste 14 cut from the plastic film is not passed.
However, the operator detects the waste 14 through the
operation panel by viewing because the image through the
camera 23 can be displayed on the operation panel. Then, the
waste 14 can be forcibly discharged by cleaning the chute 18
physically.
[0042] Next, another embodiment including the sensors
mounted on each of the areas Al to A4 and Bl to B4 will be
explained below with reference to Fig. 5.
[0043] Fig. 5 is a front view showing the chute 18 as
viewed from the upstream side of the feed direction of the
plastic film, similarly to Fig. 4. In the embodiment, the
apparatus is configured to successively make the plastic bags
one by one. Each pouch (plastic bag) has one notch, so that
three of the partition plates 20 are disposed because the
wastes 14 are generated at four positions. The partition
plate 20 has the same depth as the chute 18 or as the
dimension B shown in Fig. 6A.
[0044] The chute 18 includes projection portions on its
inner surface side as shown in Fig. 6B so as to nip the
partition plates to be positioned by the projection portions.
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The projection portions are preferably spaced from each other
at a narrow pitch so as to change the position of the
partition plates 20 of Figs. 4 and 5. It is enough that the
projection portions are disposed in the range of the
dimension C shown in Fig. 6A. The position of the partition
plate 20 can be changed widthwise Y of the plastic film
depending on where the partition plate 20 is nipped between
the projection portions.
[0045] As shown in Fig. 6D, in stead of the above
projection portions, mountain shaped projection portions may
be disposed and spaced from each other at a narrow pitch, and
the partition plates 20 may have V shaped grooves
corresponded to them. Thus, the positon of the partition
plate 20 can be changed in the same way.
[0046] As shown in Fig. 6C, grooves may be disposed in the
inner surface of the chute 18 in such a way that the
partition plate can be nipped between the grooves so as to be
positioned. The grooves may be disposed in a direction
normal to the feed direction of the plastic film and along
the fun shape of the chute 18 radially so as to be extended
to the end of the partition plate shown in Fig. 5. Therefore,
the partition plates can be set at predetermined positions
only by putting the partition plates into the grooves
optionally.
[0047] As shown in Fig. 6A, even if the width of the
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plastic film is smaller than the width of the chute 18, the
thickness of the upper blade 5 is the same as dimension B,
and the width of the upper blade 5 is the same as the width
of the chute 18. Thus, the open portions having a dimension
B generated when cross cutting and disposed on the both sides
of the plastic film can be covered by the upper blade 5.
Therefore, the suction air does not leak at the both sides of
the chute 18 so that the efficiency of the suction cannot be
lowered when cross cutting.
[0048] As shown in Fig. 5, a plurality of pairs of
projectors 23 and receivers 24 as optical sensors are
disposed between the partition plates 20 and in the areas Al
to A4 and B1 to B4 respectively. The operation of each of
the sensors is started at the same time when the upper blade
5 shown in Fig. 6A is moved, and the pairs of the projectors
23 and the receivers 24 detect the waste 14 passing between
them in the areas A and B during the suction. The timing of
the operation of the sensor is the same as the timing of the
open of the above-described electronic shutter of the camera.
The apparatus determines that the waste 14 is not passed
through the path when any one of the four paired projectors
23 and the receivers 24 does not detect the waste 14, in
which each of the four pairs is disposed in each of the four
areas Al and Bl, A2 and B2, A3 and B3 and A4 and B4. Then,
the alarm is worked and the apparatus is stopped until the
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cross cut starts. On the other hand, the apparatus
determines that the waste 14 is passed through the path and
the alarm is not raised when the waste 14 is detected by the
sensor of either of the areas A and B.
[0049] Even in this case, the algorithmic pattern 2 may be
operated when a stricter detection is needed as above
described, and the apparatus may determine that the waste 14
is passed through the path only if the waste 14 is detected
by the sensor of the both areas A and B.
[0050] The sensor may be composed of a fiber sensor so as
to detect the waste 14 having a size at least about 2mm by
lOmm by 0.1mm minimum.
[0051] A material with an antistatic property may be
preferably used for the walls of the divided paths 21A, 21B,
21C and 21D. For example, a metallic material, or a plastic
material with a conductive property into which a carbon black
is kneaded may be preferably used.
[0052] Further, an airtight material may be preferably
used for the walls of the divided paths 21A, 21B, 21C and 21D.
For example, the airtight thereof can be improved in a way
that a main material is composed of metal, and a conductive
rubber is used at the connected portion of the suction chute
18. The position of the conductive rubber is disposed below
the position of the projection portion in such a way that the
waste 14 cannot be engaged with the rubber as much as
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possible.
[0053] Each of the divided paths 21A, 21B, 21C and 21D has
a smooth flow channel geometry preferably. For example, the
wall surface is extended linearly, and the width of each of
5 the wall surface and the groove becomes narrower from the
upside to the downside so that the partition plate can easily
be inserted and removed from the upside so as to be moved
between the grooves.
[0054] The partition plate 20 can preferably be moved
10 widthwise Y of the plastic film 1. The mechanism is not
limited to the above structure of Figs. 6B to 6D.
DESCRIPTION OF REFERENCE NUMBERS
[0055]
15 1 plastic film
14 waste
15A, 15B, 15C, 15D area
16 suction path
17 airflow
20 20 partition plate
21A, 21B, 21C, 21D divided path
22 detect position
23 CCD camera
24 detect area
26 controller
